code: def testOne(self):
      self.assertEqual(DerivativeSFX()([1234]), (1.0, 1234))
  
file_path: essentia/test/src/unittests/sfx/test_derivativesfx.py
imports: from essentia_test import *
  import numpy
label_desc: Use image node_id 3 for calling the TestDerivativeSfx obj's underlying member method code with example usage: obj.testOne() without return types